This invention relates to marine drives, and more particularly to particularly to an improved propeller mounting for such drives in both outboard motor and stern drive applications.
Heretofore, it has been observed that the aft portions of some marine shafts have tended to fracture or break off adjacent the propeller hub. Furthermore, the splined aft sections of some marine propeller shafts have been subject to undesirable corrosion.
It has been determined by the inventor that the first problem has been caused by lack of concentricity in the propeller shaft mounting, while the second problem has been due to lack of sufficient sealing adjacent the splined shaft portion.
It is an object of the present invention to solve these problems in a unique manner, while more adequately securing the propeller shaft.
In accordance with the various aspects of the invention, a marine drive for a boat includes a longitudinally extending propeller shaft which effectively carries the propeller hub between a pair of fore and aft conical surfaces which mate with similar conical surfaces associated with the hub. These mating surfaces restrain orbiting movement of the propeller to essentially eliminate fracturing or breaking of the propeller shaft. The mating surfaces also center the hub on its axis and provide for high torque retention. The construction is such that corrosive water is kept out of the joint between the hub and propeller shaft, with pre-applied lubricant being retained therein.
The inventive concepts may be utilized with a single propeller system, or a dual propeller installation.